In this Oct. 2009 file photo, an Afghan Commando and a U.S. Soldier from 20th Special Forces Group take part in a training exercise in Afghanistan's Wardak Province. U.S. soldiers serving in one of southern Afghanistan's most violent areas say they are successfully training the Afghans to secure their country and their progress so far will play a large role in determining how many more American troops President Barack Obama sends home next year. (AP Photo/Maya Alleruzzo, File)

In this April 2010 file photo, Afghan National Army recruits practice a house clearing during training exercise in Kabul, Afghanistan. U.S. soldiers serving in one of southern Afghanistan's most violent areas say they are successfully training the Afghans to secure their country and their progress so far will play a large role in determining how many more American troops President Barack Obama sends home next year. (AP Photo/Dar Yasin, File)

In this Sept. 2009 file photo, U.S. Army Sgt. William Womack, 23, from Batesville, Ga., of the 118th Military Police Co., based at Fort Bragg, N.C., is prone during a training session for the Afghan National Police at a combat outpost in the Jalrez Valley in Afghanistan's Wardak Province. U.S. soldiers serving in one of southern Afghanistan's most violent areas say they are successfully training the Afghans to secure their country and their progress so far will play a large role in determining how many more American troops President Barack Obama sends home next year. (AP Photo/Maya Alleruzzo, File)

In this April 2012 file photo, Afghan special forces demonstrate a raid for rescuing a hostage during a showing to NATO Secretary-General Anders Fogh Rasmussen, unseen, at the commando training center in Kabul, Afghanistan. U.S. soldiers serving in one of southern Afghanistan's most violent areas say they are successfully training the Afghans to secure their country and their progress so far will play a large role in determining how many more American troops President Barack Obama sends home next year. (AP Photo/Musadeq Sadeq, File)